Ground beetles in city forests: does urbanization predict a personality trait?

Background. Urbanization leads to substantial changes in natural habitats with profound effects on wildlife. Understanding behavioural responses to such environmental change is essential for identifying which organisms may adapt, as behaviour is often the first response to altered conditions. Individuals in more urbanized habitats may be expected to be more exploratory and bolder than their conspecifics in less urbanized habitats as they may be better able to cope with novel challenges. Methods. In a two-year field study we tested ground beetles from differently urbanized forests for their exploratory behaviour (in a novel environment) and their risk-taking (death-feigning). In total, we tested ca. 3,000 individuals of four forest-dwelling ground beetle species from eight within-city forest patches. In the second year, we also transferred ca. 800 tested individuals of two species to the laboratory to test for consistent behavioural differences (i.e. personality differences) under standardised conditions. Results. Individuals were generally more exploratory in more urbanized than in less urbanized areas but only in one year of the study. Exploratory behaviour was not predicted by population density but increased with temperature or showed a temperature optimum. Exploration was consistent over time and individuals that were more exploratory also took higher risks. Discussion. We demonstrated that species which are generally less directly exposed to human activities (e.g., most invertebrates) show behavioural responses to urbanization. Effects of urbanization were year-dependent, suggesting that other environmental conditions interacted with effects of urbanization on beetle behaviour. Furthermore, our results indicate that different personality compositions might cause behavioural differences among populations living in differently urbanized habitats

Evaluation of landscape-level grazing capacity for domestic sheep in alpine rangelands

Balancing the number of grazing animals with the level of plant resources is a core issue in grazing management. Complete, full-coverage vegetation surveys are often used for this purpose, but these are expensive undertakings. We have presented a method to downscale information from regional sampling surveys by poststratification using a land cover map derived from satellite-based measures of reflectance values. This approach opens new prospects for landscape-level evaluation of productivity. We applied this method to eight grazing districts (19-245 km2) in Setesdal Vesthei, Norway, in 2006. Sheep densities in three of eight grazing districts of Setesdal Vesthei fluctuated above the estimated grazing capacity. We fitted 43 sheep with Global Positioning System collars in two contrasting grazing districts in 2007-2008 to assess their selection of the land cover productivity classes in the map used for poststratification. In the area with high vegetation coverage, sheep selection increased in areas with an overall higher productivity, supporting the main basis of the approach. However, in the grazing districts with lower vegetation coverage, selection was higher for areas of overall low vegetation productivity. The likely explanation is the presence of small areas of snow bed vegetation with high-quality forage in areas with a generally rocky surface. Our study provides a first step toward a grazing capacity evaluation to achieve a sustainable management of sheep on alpine ranges of Scandinavia, and our approach is likely applicable to other open alpine ranges in the northern hemisphere. © 2014 The Society for Range Management.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information